Sorry about the delay caused in getting back to you.
We have analyzed your query and we are tried to achieve your requirement by setting the IsDropDownOpen as True.
We have done this by listening the CurrentCellLoaded event.
Please refer the following code snippet.
void dataGrid_CurrentCellLoaded(object sender, GridCurrentCellLoadedEventArgs e)
var combobox = (e.UIElement as GridCellComboBoxDropDown);
if (combobox != null)
combobox.Dispatcher.BeginInvoke(new Action(() =>
combobox.IsDropDownOpen = !combobox.IsDropDownOpen;
combobox.IsDropDownOpen = true;
We have prepared the sample based on your requirement and please find the attached sample.
Please let us know if this solution helps you.